U.S. Pat. No. 2,657,195 broadly discloses polyesters of various stilbenedicarboxylic acid isomers with glycols, aminoalcohols, and diamines. Various glycols are disclosed containing 2 to 16 carbon atoms, but copolyesters of 1,6-hexanediol and ethylene glycol are not specifically disclosed.
U.S. Pat. No. 3,496,839 relates to low molecular weight homopolymers of 4,4'-stilbenedicarboxylic acid and aliphatic glycols useful in radiation-cured cross-linked polyester coatings. Column 2, lines 20 to 44, contain a general listing of the glycols useful in these coatings. No examples are given using a combination of 1,6-hexanediol and ethylene glycol. Neither U.S. Pat. No. 2,657,195 nor U.S. Pat. No. 3,496,839 distinguishes one stilbenedicarboxylic acid isomer from another, i.e., 4,4'- from 3,3'- or cis- from trans-, etc.
Our own U.S. Pat. No. 4,420,607 (issued Dec. 13, 1983), U.S. Pat. No. 4,459,402 (issued Feb. 10, 1984), U.S. Pat. No. 4,468,510 (issued Aug. 28, 1984), U.S. Pat. No. 4,526,822 (issued July 2, 1985) all disclose polyesters based on trans-4,4'-stilbenedicarboxylic acid using various glycols. No exaples of copolyesters based on the glycols claimed herein are specifically disclosed.
Our U.S. Pat. No. 4,551,520 discloses copolyesters based on terephthalic acid, trans-4,4'-stilbenedicarboxylic acid and 1,4-cyclohexanedimethanol.
Other patents which disclose trans-4,4'-stilbenedicarboxylic acid are Japanese Kokai No. 72348/74 and U.S. Pat. Nos. 2,657,194; 3,190,174; 3,247,043; 3,842,040; 3,842,041 and 4,073,777. Polyesters of trans-4,4'-stilbenedicarboxylic acid and neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol are disclosed by Meurisse, et al., in the British Polymer Journal, Vol. 13, 1981, page 57 (Table 1). Jackson and Morris disclose homopolyesters from trans-4,4'-stilbenedicarboxylic acid and various aliphatic glycols in the Journal of Applied Polymer Science, Applied Polymer Symposia, 41, 307-326 (1985). Our copending applications filed of even date herewith entitled "Polyesters of trans-4,4'-Stilbenedicarboxylic Acid, 1,4-Butanediol and 1,6-Hexanediol", and "Polyesters of trans-4,4'-Stilbenedicarboxylic Acid, 1,4-Butanediol, and Ethylene Glycol" also disclose polyesters based on trans-4,4'-stilbenedicarboxylic acid. No examples of copolyesters based on stilbenedicarboxylic acid, 1,6-hexanediol and ethylene glycol are specifically disclosed.